Snowflake acts as an entry point. A lot of official TOR entry nodes are blacklisted in some contries. Since Snowflake can run basically behind any IP anywhere where a browser is, it is hard to block them. In that way users in suppressed countries can still access the TOR network through Snowflake but the official entry nodes.
I hope that means that they can and will put more power into Firefox development - to concentrate on their main thing.